I don't know if anyone has already done something like this and I'm sorry if they have I have never seen it and I thought it would make a good backdrop to why the Wizard world was the way it was.
September 23 1945 Minister for Magic office
"Minister Moon the moving picture that the Prime minister sent over is here."
"Thank you Charles please set it up and turn it on." replied minister Leonard Spencer-Moon.
As Charles was setting up the projector Moon asks some questions, "So Charles how is the headway we are making on moving Pictures with magic?"
"Very quickly" Charles says as he plugs the machine into the generator. "We have gotten to the point where still photographs can be animated for about ten second loops, and the Department of Mysteries think sound could be added if but for a limited amount of time."
"Oh very good and remind me what the Prime Minister said this was again?"
"I don't know sir" replies Charles as he flips on the projector and starts turning the hand crank, "The film just said Hiroshima, the end of the war."
What followed was five minutes of disbelief and Horror, the Muggles had created a weapon so powerful that it destroyed an entire city, the images of the epicenter of the blast were disturbing the area just beyond that even more so. "One of these could flatten London, this building, Diagon Alley," the minister was terrified.
"Sir this could probably take out Hogwarts, wards in all."
"The people will panic when they find out."
Gears are turning in the head of the chief assistant and adviser to the Minister for Magic and the real reason he is there comes through. "Do they need to find out?"
Panic turns to contemplation and then resigned acceptance on Moon's face. "I always did like the muggles we have been working with these past five years but you're right we have to contain this."
"I as always promise you my silence," replied Charles
"And I thank you for that you do the Potter name proud now help me draft the letter to the Prime Minister about how we need to immediately cease correspondence because the war is over and for some reason the Statute of Secrecy needs to be upheld."
"Of course sir."
Little did they know that the new policies of isolationism would ruin their world more than the knowledge of those bombs ever could. It sowed distrust between muggle-born and Pure Bloods, left them in the past, and paved the way for evil to rear it's head in there once great nation.